I'm so sorry! Did you start a true flow? I hate to say this but it sounds like a chemical to me, especially since your LP was longer than normal.
I felt like I had the flu like that a few days during my last cycle which was a chemical, and my lines were light and inconsistent. That flu like feeling is actually my first sign every time I'm pregnant.
I am so sorry to hear about the cramps and spotting. Please keep us updated! Sending you love and hugs!